High Temperature Breakdown of Sodium Chloride

Abstract

IT is generally accepted that the electric strength of alkali halide single crystals rises to a maximum at some critical temperature¹, depending on the particular alkali halide as well as secondary factors such as the density of impurities, the amount of mechanical strain present and the form of the applied voltage. According to Kuchin², the critical temperature for NaCl is about 20° C for 100 µs impulses and about 80° C for 0.1 µs impulses, while for KBr von Hippel and Alger³ found a critical temperature of about 200° C when the applied voltage had a rise time of 10⁻³ s. Cooper⁴ found that the addition of 0.022 mole per cent of lead reduced the critical temperature of KCl from about 110° C to − 120° C.